Effects of Dehydration on Motor Skills, Attention, and Performance in Adolescent Football Players

NCT ID: NCT07320313

Last Updated: 2026-01-06

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 75 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-01-23
• Study Completion Date: 2025-04-30

Brief Summary

This study aims to investigate how hydration status affects attention, motor competence, and football skills in adolescent male football players aged 13-14 years. Participants will complete standardized cognitive, motor, and sport-specific tests under two conditions: normal hydration (euhydration) and controlled dehydration (hypohydration). Hydration levels will be assessed using urine colour and body mass measurements, while attention and motor skills will be evaluated with validated tools. The study seeks to understand the impact of fluid balance on physical and cognitive performance in young athletes, without altering their usual routines.

Detailed Description

This comparative, quasi-randomised, counterbalanced, repeated-measures study investigates the effects of hydration status on cognitive function, motor competence, and football skills in adolescent male football players aged 13-14 years. A pilot study with 15 participants was conducted to determine effect size (Cohen's d = 0.43) and assess feasibility, confirming that a minimum of 73 participants would be required for the main study.

Seventy-five participants met strict inclusion criteria, including voluntary participation, no chronic or metabolic diseases, and a homogeneous sporting background. Participants had a mean age of 13 ± 1 years, height of 148 ± 5 cm, weight of 42 ± 5 kg, and BMI of 19.1 ± 1.2 kg/m². Most trained 8-10 hours per week and had 3-4 years of competitive football experience.

Each participant was tested under two hydration conditions: euhydration and hypohydration. In the euhydration condition, participants maintained regular fluid intake for 12 hours prior to testing and consumed 500 ml of water with a standardised breakfast. Hydration status was verified using first-morning urine samples and Armstrong's eight-point urine colour scale. In the hypohydration condition, participants underwent controlled fluid restriction and a treadmill walking protocol to achieve a 2-3% body mass loss. Pre- and post-exercise body weight and urine measurements were used to quantify hypohydration.

Following each testing session, participants completed the d2 Attention Test, the Bruininks-Oseretsky Test of Motor Proficiency - Short Form (BOT-2 SF), and a structured football skill test assessing passing, dribbling, and shooting accuracy. All procedures were performed under supervision in controlled environmental conditions, with scheduled rest intervals to prevent fatigue and ensure safety. Secondary checks included urine strip tests, while perceived exertion and local muscle discomfort were monitored continuously.

The study design allows for within-subject comparisons across hydration conditions to determine how fluid balance affects attention, motor skills, and sport-specific performance in adolescent athletes. Data will be analyzed to provide insights into the relationship between hydration and physical-cognitive performance in young football players, with implications for training and competition strategies.

Conditions

Hydration Status; Sport Performance; Football; Adolescent Athletic Performance; Cognitive Function and Well-Being

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Euhydration Condition

Participants completed the euhydration condition first. They maintained habitual fluid intake for approximately 12 hours prior to testing, consuming 1.5-2.0 litres of water ad libitum during the day and night. On the morning of testing, a standardized breakfast was consumed along with 500 ml of water approximately two hours before testing. Participants were instructed not to urinate during the final 30 minutes prior to the session. Hydration status was verified using first-morning urine samples assessed via Armstrong's eight-point urine colour chart (target 1-2) and pre-test body mass measurements. Once classified as adequately hydrated, participants completed the d2 Attention Test, the Bruininks-Oseretsky Test of Motor Proficiency - Short Form (BOT-2 SF), and a structured football skill test. Attention and motor tests were conducted indoors, followed by the football skill test on an outdoor pitch. All testing was performed under supervision, with small participant groups to ensure st

Group Type: EXPERIMENTAL

Euhydration Protocol

Intervention Type: BEHAVIORAL

Participants maintained their habitual fluid intake for 12 hours prior to testing, approximately 1.5-2.0 L ad libitum throughout the day and night, and consumed 500 mL of water with a standardized breakfast approximately two hours before the test. Participants were instructed to refrain from urinating during the 30 minutes preceding testing. Hydration status was verified using first-morning urine colour assessed on Armstrong's 8-point scale (target range 1-2) and pre-test body mass measurements. Cognitive, motor, and football skill performance were subsequently evaluated under these euhydrated conditions using the d2 Attention Test, BOT-2 SF, and a structured football skill test, respectively.

Hypohydration Condition

After completing the euhydration condition and following a minimum 48-hour washout period, the same participants completed the hypohydration condition. Fluid intake was restricted beginning at 17:00 the day before testing, with no fluids overnight, and a low-fluid breakfast was provided on the morning of the session. Hypohydration was induced via a controlled treadmill walking protocol, with speed and duration individually adjusted to achieve 2-3% body mass loss. Participants were continuously monitored for heart rate, perceived exertion (Borg 6-20 scale), and localized muscle discomfort. Body mass was measured every 10 minutes, and fluid intake was not permitted during exercise. Hydration status was confirmed via pre- and post-exercise urine colour and body mass measurements, with urine strip tests as a secondary check. After a 15-minute seated recovery and consumption of low-water snacks, participants repeated the d2 Attention Test, BOT-2 SF, and football skill test under hypohydrat

Group Type: EXPERIMENTAL

Hypohydration Protocol

Intervention Type: BEHAVIORAL

Participants underwent a hypohydration protocol beginning with fluid restriction from 17:00 on the day prior to testing, with no fluid consumption overnight, and a low-fluid breakfast on the morning of the session. Hypohydration was induced via supervised treadmill walking for approximately 45 ± 5 minutes at \~5.5 km/h with a 5% incline under moderate environmental conditions. No fluids were allowed during exercise, and body mass was measured every 10 minutes. Treadmill duration and intensity were individually adjusted until participants achieved a target body mass loss of 2-3%. Hydration status was confirmed via pre- and post-exercise urine colour and body mass measurements, with urine strip tests applied as a secondary verification. Following a 15-minute seated recovery period with consumption of low-water snacks, participants completed the d2 Attention Test, BOT-2 SF, and football skill test under hypohydrated conditions. Safety was continuously monitored via heart rate, Borg RPE sca

Interventions

Euhydration Protocol

Participants maintained their habitual fluid intake for 12 hours prior to testing, approximately 1.5-2.0 L ad libitum throughout the day and night, and consumed 500 mL of water with a standardized breakfast approximately two hours before the test. Participants were instructed to refrain from urinating during the 30 minutes preceding testing. Hydration status was verified using first-morning urine colour assessed on Armstrong's 8-point scale (target range 1-2) and pre-test body mass measurements. Cognitive, motor, and football skill performance were subsequently evaluated under these euhydrated conditions using the d2 Attention Test, BOT-2 SF, and a structured football skill test, respectively.

Intervention Type: BEHAVIORAL

Hypohydration Protocol

Participants underwent a hypohydration protocol beginning with fluid restriction from 17:00 on the day prior to testing, with no fluid consumption overnight, and a low-fluid breakfast on the morning of the session. Hypohydration was induced via supervised treadmill walking for approximately 45 ± 5 minutes at \~5.5 km/h with a 5% incline under moderate environmental conditions. No fluids were allowed during exercise, and body mass was measured every 10 minutes. Treadmill duration and intensity were individually adjusted until participants achieved a target body mass loss of 2-3%. Hydration status was confirmed via pre- and post-exercise urine colour and body mass measurements, with urine strip tests applied as a secondary verification. Following a 15-minute seated recovery period with consumption of low-water snacks, participants completed the d2 Attention Test, BOT-2 SF, and football skill test under hypohydrated conditions. Safety was continuously monitored via heart rate, Borg RPE sca

Intervention Type: BEHAVIORAL

Other Intervention Names

Hydration Maintenance Protocol; Normal Hydration Condition; Fluid Restriction + Exercise-Induced Dehydration Protocol

Eligibility Criteria

Inclusion Criteria

• Male sex (to avoid hormonal variability related to the menstrual cycle)
• Voluntary participation
• Age between 13 and 14 years
• Similar sporting background (regular football training and competition experience)
• No chronic or metabolic disease
• No respiratory or renal disease
• No medical condition requiring fluid restriction
• Not taking any medications or dietary supplements (e.g., vitamins, minerals, creatine, protein)
• No recent history of injury

Exclusion Criteria

• Outside the specified age range
• Female sex
• Diagnosis of chronic/metabolic, respiratory, or renal disease
• Regular use of medication, diuretics, or dietary supplements (e.g., vitamins, - minerals, creatine, protein)
• Medical condition requiring fluid intake restriction
• Not engaged in sports or without a football background
• Recent injury history

• Minimum Eligible Age: 13 Years
• Maximum Eligible Age: 14 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

bekir tokay

OTHER

Sponsor Role: lead

Uşak University

OTHER

Sponsor Role: collaborator

Responsible Party

bekir tokay

Instructor, Ph.D

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Mustafa AKIL, Professor Doctor

Role: STUDY_CHAIR

Uşak University, Department of Sports Science

Locations

Faculty of Sports Sciences

Uşak, Uşak, Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

548-548-10

Identifier Type: -

Identifier Source: org_study_id